Douglas Hofstadter wrote Gödel, Escher, Bach in the late 1970s. He used the short-hand “strange loops”, but dedicates a good bit of time considering this very thing. It’s like the Ship of Theseus, or the famous debate over Star Trek transporters—at what point do we stop being an inanimate clump of chemical compounds, and become “alive”. Further, at what point do our sensory organs transition from the basics of “life”, and form “consciousness”.

I find anyone with confident answers to questions like these immediately suspect.